At the inferior end of the trachea is an internal ridge of mucosal covered cartilage that initiates a cough reflex when it is stimulated; this structure is the

What are two examples of conduction that we use everyday

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Which statements best describe the atoms of the gas neon? check all that apply